Method for preparing nap molecular sieve and nap molecular sieve with white mud as raw material

Abstract

The invention provides a method for preparing a NaP molecular sieve from white mud as a raw material and the NaP molecular sieve. The method comprises the steps of (1) preparing a structure-directing agent; (2) preparing a silicon source and an aluminum source, namely extracting the white mud by using a sodium hydroxide solution, filtering and collecting filtrate for later use; (3) preparing silica-alumina gel, namely adding sodium metaaluminate and deionized water to the filtrate until the molar ratio of SiO2 to Al2O3 in the system is (2-3):1 and the molar ratio of Al to H2O is 1:(360-495), adjusting the pH value of the system to be 10-11, adding the structure-directing agent, stirring evenly and ageing to obtain the silica-alumina gel; (4) crystallizing the silica-alumina gel; and (5) carrying out post-treatment, namely filtering a crystalized product and then washing and drying the filtered product to obtain the NaP molecular sieve. According to the method, the NaP molecular sieve can be prepared by fully utilizing effective silicon and aluminum in the white mud, the waste utilization of the white mud is achieved, the preparation cost of the NaP molecular sieve is reduced and the prepared NaP molecular sieve is good in performance, large in ion exchange capacity and high in economic benefit.

Description

technical field [0001] The invention belongs to the field of molecular sieves, in particular to a method for preparing NaP molecular sieves from white mud and the NaP molecular sieves. Background technique [0002] Shenhua Group has successfully developed the world's first "one-step acid-dissolution method" new process for producing alumina from fly ash based on the characteristics of high-aluminum fly ash produced after coal combustion in the Zhungeer area. Please refer to the patent document CN102145905A. According to the process calculation, every 2.5 tons of fly ash produces 1 ton of metallurgical grade alumina and 1.5 tons of high silicon tailings (white mud). The composition of the white mud is shown in Table 1, where Los represents the loss on ignition of the white mud, and each component is represented by the oxide form of each element. [0003] The composition of table 1 white mud and the content of each composition [0004] [0005] It can be seen from Table 1...

AI Technical Summary

Problems solved by technology

At present, P-type molecular sieves are mainly produced by the full chemical reagent method. The raw materials are sodium metaaluminate, sodium hydroxide, and industrial grade water glass as the main raw materials. The high cost greatly reduces their market competitiveness.

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